Ultrathin Ni-MOF Nanobelts-Derived Composite for High Sensitive Detection of Nitrite

In this paper, the Ni/NiO ultrathin nanobelts were successively synthesized by a facile in suit conversion process using pre-synthesized Ni-based metal-organic frameworks (MOFs) nanobelts as parent materials to detect the nitrite (NaNO₂). The synthesized Ni/NiO composites have the advantages in structure, as follows: (I) Interleaved 3D reticulated structure has strong mechanical stability; (II) Ultrathin nanobelt structures allow more active sites to be exposed and make the transfer of charge faster; (III) A large number of ultrafine Ni nanoparticles decorate the building blocks of the NiO nanobelt and enhance the electrical conductivity. Ni/NiO/GCE has an obvious oxidation peak at 0.78 V, when the concentration is between 0.5 and 1000 μM, the oxidation peak current of NaNO₂ is linearly related to the concentration, and the sensitivity is 1.5319 μA mM^-1 cm^-2 (S/N = 3). Moreover, the experimental results also concluded that the Ni/NiO ultrathin nanobelts not only indicated wonderful reproducibility in the determination of NaNO₂ in the pickled pork samples, but also could be well-recovered and keep stable for a long time.